In the past I have described various ways for producing a flexible solar collector material which has a plurality of glass spheres adhered to one surface of the substrate. In U.S. Pat. No. 4,033,324 which issued on July 5, 1977, I described an arrangement for mounting a plurality of focusing elements on a solar energy absorbing substrate. The elements focus solar energy rays into a series of hot spots focused on the surface of the substrate which provides a high temperature for transfer of the heat energy to the opposite side of the substrate material.
In U.S. Pat. No. 4,054,125 I describe an arrangement whereby a dark colored absorbing substrate covered with the monolayer of the transparent spheres is provided for absorbing solar radiation for heating an air column formed between the substrate and the inside of a transparent window. In one form of this invention a drapery material forms with the substrate a series of tubes for naturally or forcibly circulating warm air through the tubes when the substrate is heated by solar radiation. Reflecting cover material, selectively mountable in front of the monolayer substrate, reflects solar radiation back through the transparent window when heating is not required.
My presently pending patent application Ser. No. 224,630 describes a unique method for forming a stable, monolayer of transparent spheres on a sheet-like substrate by flowing a stream of spheres in a cascading arrangement over the sloped surface of the substrate material coated with a suitable adhesive. The spheres which adhere to the substrate material, are then set by either applying light pressure or the application of a thin film of clear transparent material. This provides a novel substrate material having a fairly complete cover of uniform sized glass spheres adhered to one side of the surface of the material to form the solar concentrating function.
When the material which is formed by this method is utilized in the fabrication of window covers or shades, it performs a very useful function. When in the drawn position, the solar energy which impinges on the outer surface of the shade heats the inside surface of the substrate film which in turn heats the air next to the film causing the heated air to rise by convection. In addition, heat energy is also radiated into the room directly by the heated interior surface of the substrate film. In this way, solar energy is transformed into heat energy which is utilized for heating the interior of a room or other enclosed area.
In the use of this material, it has been found that a considerable increase in the efficiency of the device can be obtained by sealing the edge of the shade along all edges of the window in order to trap the cold air next to the window forming an insulating factor and preventing the cold air from escaping into the interior of the room. With this arrangement the seal becomes very effective during the night time hours.
As can be expected, there are many difficulties in attempting to seal the edges of a window shade of this type. One of these is the necessity to be able to raise and lower the shade at will. In order to do this, it is necessary to be able to quickly and easily release the bottom and side edges of the window shade as desired when it is necessary to raise or lower the shade. It is also necessary that the seal for this type of device be easily released or attached so that by merely raising and lowering the shade and putting it in place the seal can be made or broken.
In the past it has been attempted to use a slotted channel on each side of the shade to hold and retain the edges of the shade in close proximity to the window frame to form a quasi air-tight seal. As can be readily expected if the channel is very narrow, it is difficult to move the shade. With this hindrance, it makes it difficult to use the shade with the final result that the shade is either pulled from the channels or the sides are cut or torn rendering any seal useless. In addition, the bottom of the shade is seldom properly retained, or if it is it is by use of a mechanical seal or lock which usually is very cumbersome and difficult to use.
The present invention solves all of these problems by rendering a very quick and easy seal which is completely or is substantially air-tight when in place. When combined with a solar collector type device, unique and gratifying results are obtained with the applicant's invention.